Device for lighting burners in a household appliance, in particular a cooking  or barbecue range

ABSTRACT

A device including high voltage generating means accommodated in an electrical insulating casing, spark generating means adapted to be arranged near respective burners of a household appliance to be ignited and electrical connection means between the high voltage generating means and the spark generating means; the high voltage generating means include a single secondary winding of a transformer provided with a single high voltage output contact and a single return contact, connectable to ground; the spark generating means include for each burner a pair of electrodes reciprocally insulated and arranged side-by-side at a predetermined distance such that to allow in use the generation of sparks between the same; the electrical connection means include a single electrical wire connected to a single output of the high voltage generating means connecting in series together all the existing electrode pairs and divided by the electrodes of each pair of a plurality of segments reciprocally and electrically insulated by means of the electrodes of each electrode pair, to form a chain of electrodes coupled two-by-two.

TECHNICAL FIELD

The present invention relates to a lighting device particularly suitablefor cost-effectively and simply lighting a plurality of burners in ahousehold appliance, in particular consisting of a multiple burnercooking or barbecue range.

BACKGROUND ART

It is known that nowadays household appliances provided with burners fedby a combustible gas (e.g. cooking ranges, barbecue ranges, gas ovens,etc.) are all essentially equipped with either manually or automaticallycontrolled electronic ignition devices, preferably operating on eachexisting burner.

The known ignition devices consist in a casing containing high voltagegenerating means based on one or more transformer spools including aplurality of secondary (high voltage) windings, each of which presentsan output contact connected to an ignition electrode positioned inproximity of a corresponding burner; in use, the secondary windingsapply voltage to the electrodes, which close the high voltage circuitwith the metallic structure of the burners, which is connected to groundby means of the cooking range (generally formed by conducting material)thus generating sparks between electrodes and burners which produce theignition of the combustible gas in the meantime fed to the burners, e.g.by means of valves or solenoid valves.

The traditional ignition devices of the described type present thedouble drawback of being relatively costly, complex and cumbersome, dueto the numerous electrical power wires needed to connect the electrodesto the corresponding outputs (output contacts) of the high voltagegenerating means; and of being needed to be designed according to thenumber of burners to be ignited; therefore a device having the casingwith high voltage generating means provided for igniting, e.g., threeburners cannot be used to ignite a higher number of burners, while, if alower number of burners needs to be ignited, the unused output(s) mustbe somehow neutralised, e.g. by means of a direct connection to ground.

DISCLOSURE OF INVENTION

It is the object of the present invention to solve the aforesaiddrawbacks by providing a very simple, low cost and small size ignitiondevice, which is capable of simply igniting a plurality of burners,present in variable number within a predetermined range, so as to beadapted to serve different models of cooking/barbecue ranges, having adifferent number of burners to ignite, essentially without changing anyof the basic structure of the device itself and above all of the highvoltage generating means.

The present invention thus relates to a device for igniting the burnersof a household appliance, in particular a cooking or barbecue range, asdefined in claim 1.

In particular, the ignition device according to the invention compriseshigh voltage generating means consisting of a single secondary windingof a transformer provided with a single high voltage output contact anda single return contact, connectable to ground; and spark generatingmeans including, for each burner to be ignited, a pair of electrodesreciprocally and electrically insulated and reciprocally arrangedside-by-side at a predetermined distance such that to allow thegeneration of sparks in use between the electrodes of the electrodepair.

Finally, the device according to the invention comprises electricalconnection means between the high voltage generating means and the sparkgenerating means including a single electrical wire, a first end ofwhich is connectable to the single output connector of the high voltagegenerating means and a second end of which is connectable to ground;such single electrical wire connects together in series all of theexisting electrode pairs and is subdivided by the electrodes of eachelectrode pair into a plurality of segments reciprocally andelectrically insulated by the electrodes of each electrode pair, to forma chain of electrodes paired two-by-two.

Furthermore, the single secondary winding is dimensioned so as to beadapted to generate a sufficient voltage to produce the generation ofsparks between the electrodes of each pair of electrodes for apredetermined number of pairs of electrodes and equal to the maximumnumber of burners applicable to the household appliance.

In this manner, the same device again using the same high voltagegenerating means, having an appropriately dimensioned secondary winding,may be used to ignite any number of burners, i.e. at least in the entirepossible range of a same household appliance, simply by connecting it toan appropriate number of electrode pairs in series by means of segmentsof electrical wire.

According to an aspect of the invention, such electrode pairs arrangedside-by-side form ignition assemblies, each of which includes anelectrically insulating body provided with fastening means to thehousehold appliance; one pair of electrodes carried and accommodated inthe electrically insulating body except for respective bare endsprotrudingly carried side by side by the insulating body; and a pair ofcontacts, each connected to a respective electrode.

The contacts of each ignition assembly are then in use connected bymeans of the mentioned wire segments in series together, in particular afirst contact is connected in series to a corresponding opposite contactof an immediately preceding ignition assembly, e.g. closer to the highvoltage generating means, and a second contact is connected in series toa corresponding opposite contact of an immediately following ignitionassembly, for example farther from the high voltage generating means; onthe other hand, the first contact of the ignition assembly closer to thehigh voltage generating means will be connected to the single outputcontact of the high voltage generating means, while the ignitionassembly farther from the latter will have its second contact connected,by means of a terminal segment of the single electrical wire, to thereturn contact of the high voltage generating means.

In the case of gas cooking burners, each ignition assembly consists of aceramic spark plug carrying at least partially and internally embeddedthe electrodes of each electrode pair arranged side-by-side.

In this case, the invention further extends to a burner for a householdappliance comprising a gas ring and a ceramic plate arranged in use overthe gas ring, wherein the gas ring presents a radial recess open towardsthe plate and accommodating the ceramic spark plug, arranged with thepair of electrodes essentially perpendicular to the plate and in a moreinternal radial position within the radial recess, so that the ignitionassembly is in use covered by the plate.

In this manner, the electrical connections to be made are hugelysimplified, making the assembly of the device of the invention morerapid and cost-effective and the dimensions are likewise reduced.Furthermore, the burner provided with an ignition assembly consisting ofa double electrode spark plug is of particularly appealing appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will beapparent from the following description of two non-limitativeembodiments thereof, made with reference to the accompanying drawings,in which:

FIG. 1 diagrammatically shows the layout diagram of an ignition devicemade according to the invention;

FIGS. 2 and 3 respectively show an enlarged detail and a complete layoutof an ignition device according to the invention for the burners of abarbecue range, shown in perspective view; and

FIG. 4 diagrammatically depicts an enlarged detail of a component of theignition device in FIG. 1 in the case of a cooking range burner.

BEST MODE FOR CARRYING OUT THE INVENTION

With specific reference to FIGS. 1 and 2, numeral 1 indicates as a wholea device 1 for lighting burners 2, in particular longitudinal burners 2a, in a household appliance 3, in particular a barbecue range 3 a shownonly in part for the sake of simplicity.

Device 1 comprises high voltage generating means 4 accommodated withinan electrically insulating casing 5, spark generating means 6 adapted tobe arranged near respective burners 2 to be ignited of the householdappliance 3 and electrical connection means 7 between high voltagegenerating means 4 and spark generating means 6.

With specific reference to FIG. 1 and to the non-limitative embodimentin FIGS. 2 and 3, high voltage generating means 4 comprise one singlesecondary winding 10 of a transformer 11 provided with a single highvoltage output contact 12 and a single return contact 14, connectable toground. In practice, these components, along with the necessaryelectronic supply board, of the known type, are accommodated insidecasing 5, which defines an electronic ignition device of the traditionaltype, except for the fact that it indeed presents a single high voltageoutput contact 12, instead of a plurality of contacts 12, one for eachburner 2 to be ignited, as in the traditional electronic ignitiondevices; further contacts 16 carried by casing 5 allow the electricalconnection of device 1 to a power source, e.g. the electrical network.

According to the main aspect of the invention, spark generating means 6comprise, for each burner 2 to be ignited, a pair of electrodes 20,21reciprocally and electrically insulated and reciprocally arrangedside-by-side at a predetermined distance to each other such that toallow the generation of sparks 23 (FIG. 1) in use between electrodes20,21 of each existing electrode pair; while electrical connection means7 include a single electrical wire 25, a first end 26 of which isconnectable to single output contact or connector 12 of high voltagegenerating means 4 and a second end 27 of which is connectable toground, i.e. to return contact or connector 21.

Therefore, single electrical wire 25 connects together in series allexisting electrode pairs 20,21 and is subdivided by electrodes 20,21themselves of each existing electrode pair 20,21 into a plurality ofsegments 30 reciprocally and electrically insulated by electrodes 20,21of each electrode pair, to form a chain of electrodes paired two-by-two,like in the case, for example, of the known light chains.

Single secondary winding 10 is dimensioned so as to be adapted togenerate a sufficient voltage to produce sparks 23 between electrodes20,21 of each electrode pair for a predetermined number of electrodepairs, in the case in point equal to the maximum number of burners 2applicable to/provided for household appliance 3; for example, in thecase of barbecue range 3 a, if the provided models comprise a variablenumber of burners 2 a between a minimum and a maximum (there are fourburners in the case shown), winding 10 will be dimensioned to serve themaximum number of burners 2 a which may exist.

For assembly simplicity, spark generating means 6 made according to theinvention in addition to comprising a pair of electrodes 20,21 for eachburner 2, are organised in a plurality of ignition assemblies 60, eachof which (FIG. 2) includes an electrically insulating body 61 providedwith fastening means 62 to household appliance 3 and a pair ofelectrodes 20,21 carried by and accommodated in electrically insulatingbody 61 except for respective bare ends 65 protrudingly carried side bythe side by insulating body 61; finally, each assembly 60 comprises apair of contacts 66,67, each connected to a respective electrode 20,21and connected in series to respective corresponding contacts 66,67 ofthe other existing ignition assemblies 60 by means of segments 30 ofsingle electrical wire 25.

Ignition assembly 60 a arranged farther from high voltage generatingmeans 4 (FIG. 3) presents a first contact 66 connected in series to acorresponding opposite contact 67 of an ignition assembly immediatelycloser to high voltage generating means 4 and a second contact 67connected, by means of a terminal segment 30 a of single electrical wire25 to return contact 14 of high voltage generating means 4.

Therefore, as illustrated and described hereto, contacts 66,67 of eachignition assembly 60 are in use connected by means of the mentioned wiresegments 30 reciprocally in series, in particular a first contact 66 ofeach assembly 60 is connected in series to a corresponding oppositecontact 67 of an immediately preceding ignition assembly 60, e.g. closerto high voltage generating means 4, and a second contact 67 is connectedin series to a corresponding opposite contact 66 of an immediatelyfollowing ignition assembly 60, for example farther from high voltagegenerating means 4.

First contact 66 of ignition assembly 60 closer to high voltagegenerating means 4 will, on the other hand, be connected to singleoutput contact 12, while, as previously described, ignition assembly 60a will have its second contact 67 connected by means of terminal segment30 a to return contact 14, either directly as in the example in FIGS. 2and 3, or by means of the cooking range itself, i.e. through the groundconnection, in the case of a gas cooking range 3 b (FIG. 4), which isformed by metal.

With reference to the embodiment shown in FIG. 4, related to theapplication to a gas cooking range 3 b known and only diagrammaticallyshown, each ignition assembly 60 consists of a ceramic spark plug 70carrying contacts 20,21 at least partially embedded therein.

In such a case, each existing spark plug 70 is directly mounted on aburner 71 of cooking range 3 b specifically designed for the use withignition device 1 according to the invention; as shown in FIG. 4, burner71 comprises a gas ring 72 and a plate 73, e.g. formed by ceramic,arranged in use over gas ring 72; this presents a radial recess 74 opentowards plate 73 and accommodating an ignition assembly 60, in the casein point consisting of a double electrode spark plug 70, arranged withelectrodes 20,21 essentially perpendicular to plate 73 in a radiallymore internal position within radial recess 74, so as to be covered inuse by plate 73.

1. A device for lighting burners in a household appliance, in particulara cooking or barbecue range, comprising high voltage generating meansaccommodated within an electrically insulating casing, spark generatingmeans adapted to be arranged near respective burners of said householdappliance to be ignited and electrical connection means between saidhigh voltage electrical generators and spark generating means;characterised in that, in combination: i) said high voltage generatingmeans comprise one single secondary winding of a transformer providedwith a single high voltage output contact and a single return contact,connectable to ground; ii) said spark generating means comprising, foreach burner to be ignited, a pair of electrodes reciprocally andelectrically insulated and reciprocally arranged side-by-side at apredetermined distance such that to allowsparks to be produced in usebetween the electrodes of the electrode pair; iii) said electricalconnection means comprise a single electrical wire, a first end of whichis connectable to said single output contact of high voltage generatingmeans and a second end of which is connectable to ground; said singleelectrical wire connecting together in series all said pairs of existingelectrodes and being subdivided by the electrodes of each pair ofelectrodes into a plurality of segments reciprocally and electricallyinsulated by the electrodes of each pair of electrodes, to form a chainof electrodes paired two-by-two.
 2. A device according to claim 1,characterised in that said single secondary winding is dimensioned so asto be adapted to generate a sufficient voltage to produce sparks betweenthe electrodes of each predetermined pair of electrodes and equal to themaximum number of burners applicable to the household appliance.
 3. Adevice according to claim 1, characterised in that said spark generatingmeans comprise a plurality of ignition assemblies, each of whichincludes an electrically insulating body provided with fastening meansto the household appliance; one said pair of electrodes carried by andaccommodated in the electrically insulating body except for respectivebare ends protrudingly carried side by the side by the insulating body;and a pair of contacts, each connected to a respective electrode andconnected in series to respective corresponding contacts of saidplurality of ignition assemblies by means of segments of said singleelectrical wire.
 4. A device according to claim 3, characterised in thatone said ignition assembly arranged farther from said high voltagegenerating means presents its first said contact connected in series toa corresponding opposite contact of an ignition assembly immediatelycloser to said high voltage generating means and its second said contactconnected, by means of a terminal segment of said single electricalwire, to said return contact of the high voltage generating means.
 5. Adevice according to claim 1, characterised in that each said ignitionassembly consists of a ceramic spark plug carrying at least partiallyand internally embedded said electrodes of each pair of electrodesarranged side-by-side.
 6. A burner for a household appliance, inparticular for a gas range, comprising a gas ring and a plate arrangedin use over the gas ring, characterised in that said gas ring presents aradial recess open towards the plate and accommodating an ignitionassembly according to claim 5 arranged with the electrodes essentiallyperpendicular to the plate and in radially innermost position within theradial recess, so as to be covered in used by said plate.